1. Field of the Invention
The invention relates to a fan set and rotation speed-matching curve generation method for controlling the fan set, especially to a serial fan set operated in accordance with its rotation speed-matching characteristic curve and the method of generating, such as a rotation speed-matching curve.
2. Related Art
With the increasing operation speed of the central processing unit (CPU) and the rising demand for reducing the unit area used for circuit design, a data processing device is in need of a better heat dissipation system to enhance the stability of system operation. The serial fan set system of the invention is designed to provide fairly good heat dissipation efficiency, as such it is frequently utilized in the data processing device, requiring high heat dissipation efficiency.
The serial fan set is composed of two fans, arranged closely in sequence having mutually reverse fan rotation directions (one rotates in the forward direction, and the other rotates in the reverse direction), thus increasing the output air volume and air pressure, and improving the fan rotation efficiency.
In general, since the respective fan of the serial fan set system receives the same input voltage, as such in controlling the fan rotation speed, the input voltage of the two fans must be controlled simultaneously to control their rotation speed. However, by doing so, it would lead to the result that the two fans are capable of producing the optimized rotation speed, matching only when they are operated under the maximum operation voltage, yet when the system is operated in the range between the minimum operation speed and the maximum operation speed, the rotation speed-matching and operation efficiency of the serial fan set system are not quite satisfactory.
As the serial fan set system has to be operated with specific rotation speed ratio (since its rotation directions are mutually reverse, the rotation speeds of the two fans affect each other), and the rotation speed ratio at the respective rotation speed operation point is not quite the same, as such the operation of the serial fan set can not be maintained with optimum efficiency in the ordinary fan set control method of the prior art.
Therefore, how to achieve the optimum rotation speed-matching in the operation range of the serial fan set, is the most important problem to be solved, so as to achieve a breakthrough in this field.